"We showed that IL4I1 has l-amino acid oxidase activity, optimal at physiological pH and primarily directed toward phenylalanine."

"Both proteins were secreted into the culture medium, and we observed the secretion of endogenous human IL4I1 (hIL4I1) protein in a mediastinal lymphoma B-cell line, MedB-1."

"hIL4I1 inhibited the proliferation of CD3-stimulated T lymphocytes with a similar effect on CD4(+) and CD8(+) T cells. In contrast, memory T cells were more strongly affected by hIL4I1 and its catabolite H(2)O(2) than naive T cells. hIL4I1 inhibitory effect was dependent on enzymatic activity and H(2)O(2) production"

"Immunohistochemical analysis of secondary lymphoid organs showed staining of germinal center macrophages and inflammatory myeloid cells. In vitro, functional enzyme was highest in mature dendritic cells (DCs), suggesting a role in antigen-presenting cell/T-lymphocyte cross-talk."

"we demonstrate for the first time that human spermatozoa possess interleukin-induced gene 1 (IL4I1), an l-amino acid oxidase (LAAO) which is capable of generating ROS on exposure to aromatic amino acids in the presence of oxygen."

"the enzyme was located in the acrosomal region and midpiece of these cells."

"The preferred substrates were found to be phenylalanine and tryptophan"

"Stimulation of LAAO activity resulted in the induction of several hallmarks of capacitation including tyrosine phosphorylation of the sperm flagellum and concomitant activation of phospho-SRC expression. In addition, stimulation of LAAO resulted in an increase in the levels of acrosomal exocytosis in both the presence and absence of progesterone stimulation"

"We show that IL4I1 stimulates the generation of Foxp3(+) regulatory T (Treg) cells in vitro from human and mouse T cells."

"Analysis of Treg-cell induction under conditions of Phe deprivation and hydrogen peroxide addition suggests that Phe consumption by the enzyme participates in Treg-cell enrichment. In line with this hypothesis, IL4I1 inhibits mTORC1 signaling shortly after T-cell activation."

"Conversely, IL4I1 limits Th1 and Th2 polarization while modifying the Th17 phenotype, in particular, by inducing its own production."

"we show that IL4I1 activity is not only directed against phenylalanine, as initially described, but also at a lower level against arginine."

"The N92D SNP leads to a hyperactive enzyme, while the R102G mutation is hypomorphic."

"Focal secretion of IL4I1 into the immune synaptic cleft and its binding to CD3+ lymphocytes could be important in IL4I1 immunosuppressive mechanism of action."

"the presence of IL4I1 during T-cell activation decreases early signaling events downstream of TCR stimulation, resulting in global T-cell inhibition which is more pronounced when there is CD28 costimulation."

"Surprisingly, the enzymatic activity of IL4I1 is not involved."

"Here, we report on an interactome map that focuses on neurodegenerative disease (ND), connects ∼5,000 human proteins via ∼30,000 candidate interactions and is generated by systematic yeast two-hybrid interaction screening of ∼500 ND-related proteins and integration of literature interactions."

"Interactome maps are valuable resources to elucidate protein function and disease mechanisms."

"IL4I1 activates the AHR through the generation of indole metabolites and kynurenic acid."

"suppresses adaptive immunity, thereby enhancing the progression of chronic lymphocytic leukemia (CLL) in mice."

"promotes cancer cell motility, and suppresses adaptive immunity, thereby enhancing the progression of chronic lymphocytic leukemia (CLL) in mice."

"It associates with reduced survival in glioma patients"

"we constructed an IL4I1-overexpressed 293T cell line and found that IL4I1 can catalyze Trp to produce indole-3-acetic acid (IAA) and indole-3-carboxaldehyde (IAld)."

"Our results demonstrate the existence of the indole pyruvate pathway in host cells with IL4I1 as the key enzyme."

"both IAA and IAld are accumulated in dendritic cells (DCs) and can stimulate the expression of CYP1A1."

"Extracellular L-amino-acid oxidase (IL4I1) catalyzes the reaction of phenylalanine, water, and molecular oxygen to form keto-phenylpyruvate, ammonia, and hydrogen peroxide. IL4I1, inferred to form a complex with FAD, has L-amino acid oxidase activity and with a strong preference for phenylalanine."